Process for treating a cellulosic textile fabric with an insoluble telluride to render the fabric resistant to attack by micro-organisms



United States Patent PROCESS FOR TREATING A CELLULOSIC TEX- TILE FABRIC WITH AN INSOLUBLE TELLURIDE TO RENDER THE FABRIC RESISTANT TO AT- TACK BY MICRO-ORGANISMS Brenda J. Trask, Metairie, and Ralph J. Brysson, New Orleans, La., assignors to the United States of America as represented by the Secretary of Agriculture No Drawing. Filed Dec. 23, 1965, Ser. No. 516,102

1 Claim. (Cl. 117138.5)

A non-exclusive, irrevocable, royalty-free license in the invention herein described, throughout the world for all purposes of the United States Government, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the United States of America.

This invention relates to the treatment of textile materials. More particularly, the invention relates to the treatment of textile fabrics, composed mainly of cellulose. The cellulosic textiles produced by this treatment have outstanding resistance to micro-organisms and outdoor weather.

In general, this invention relates to the treatment of textile materials composed mainly of cellulose with tellurides so that the cellulose textile material exposed to direct or indirect sunlight is rendered resistant to attack and staining by micro-organisms.

It has been found that essentially insoluble tellurides when applied to cellulosic textiles render these textiles resistant to attack by micro-organisms when exposed to direct or indirect sunlight.

It is an objective of the present invention to provide a new method for rendering outdoor fabrics impervious to attack by micro-organisms when exposed to direct or indirect sunlight.

It has been found that the objects of the present invention can be achieved by treatment of the cellulosic fabric with telluride salts either by precipitation in situ alone, or precipitation in situ followed by treatment with a suitable binding resin, or by impregnation of the cellulosic fabric with an emulsion or solution of the telluride salts dispersed in a suitable binder. Suitable binders consist of, but are not limited to, alkyd resins, urea resins, melamine resins, vinyl resins, styrene resins, phenolic resins, polyethylene dispersions, butadiene-styrene copolymers, and others.

Telluride salts suitable for use in this invention are insoluble materials that contain a nonalkali metal telluride, when the metal is Sb, Bi, Cd, Co, Cu, Pb, Mn, Hg, Ni, Ag, Sn, and Zn. These compounds are effective singly, in combination, in combination with tellurium, or in combination with tellurium and each other. They may be in combination with other materials such as heavy nonalkali metal sulfides to produce various colored micro-organismresistant treated cellulosic textiles. They may be used in combination with other conventional textile treating maerials such as wetting agents, softeners, stiffeners, and others.

Preparation of these materials is not an object of this invention and may be by any suitable means.

Example 1 A dispersion of a finely divided copper telluride material containing 50% tellurium in an emulsifiable alkyd resin was applied by padding to 10.10-ounce scoured cotton duck and allowed to air dry. The ratio of copper telluride containing material to the solid resin was 2 parts to 3 parts, by weight. Approximately 1.03% copper telluride material and 1.55% alkyd resin were added to the cotton fabric. Therefore the fabric actually contained only about 0.52% tellurium. This treated duck was buried in specially composted soil consisting of 33.3 parts sweet-water sand, 33.3 parts well-rotted cow manure, and 33.3 parts top soil of high microbiological activity and maintained at a relatively constant temperature of 28 C. and of its moisture retaining capacity. Samples were removed at one week intervals and tested for strength retention, until a loss of was obtained. The treated cotton withstood six Weeks burial retaining more than 20% of its original strength while an untreated scoured duck control rotted in less than one week.

Example 2 A dispersion of finely divided cobalt telluride material containing 68% tellurium in an emulsifiable alkyd resin was applied as in Example 1 to 10.10-ounce scoured cotton duck and allowed to air dry. The ratio of the cobalt telluride containing material to the solid resin was approximately 1 to 2 parts by weight. Approximately 0.61% cobalt telluride material and 1.62% alkyd resin material were added to the cotton fabric. Therefore, the fabric actually contained only about 0.42% tellurium. This treated duck was placed on open-backed Wooden weather exposure racks in an unshaded essentially suburban area in New Orleans, La. These racks faced South at an angle of 45 and were so constructed that all the samples were at a minimum of 30 inches above the ground. After 12 months continuous exposure, the sample treated with the cobalt telluride containing material was free from any detectable mildew or other micro-organism stain or attack. A sample of untreated scoured duck was badly stained after only 4 months of exposure.

Example 3 The tellurium containing material can be dispersed with other materials to produce desired colors and shades on the treated fabric and still maintain the desired resistance to micro-organisms. A pad bath composed of the following ingredients was used to produce an olive-drab colored cotton duck:

Gms.

Cobalt telluride material (68% Te) 5.16

Chrome yellow pigment 6.0

Raw umber pigment 6.0

Lampblack 2.5 Emulsifiable alkyd resin solution (50% resin solids) 30.4

The above was dispersed by means of a sample size paint mill and emulsified in the following mixture:

Gms. 50% mineral spirits-50% toluene 190.9 Water 190.9

This mixture was applied by padding onto 10.10-ounce scoured cotton duck so as to deposit approximately 0.66 weight percent of the cobalt telluride containing material and 0.45% tellurium on the cotton fabric. A sample so treated was exposed as described in Example 2 for 12 months. The exposed sample was free from all visible signs of mildew and algae attack or staining and had retained 83% of its original strength. A scoured untreated sample simultaneously exposed showed considerable evidence of attack by micro-organisms and retained only 26% of its original strength.

Example 4 sion and air-drying. In each case the add-on of the solid 1 alkyd binder was about l.5-1.6%. The alkyd binder used here was the same as that used in the other examples.

A tabulation of the compounds and of the amount applied to the 15 samples of cotton fabric is given in Table I.

TABLE I.CONGENTRATION OF INHIBITORS APPLIED TO FABRIC Tellurium Tellurium Amount oi tellurium applied to fabric, containing in material, percent by weight material percent Antimony 62 0. 41 0. 26 0. 1O Bismuth 48 0. 42 0. 26 0. 10 Cadmium. 53 0. 41 0. 27 0. 096 Cobalt 68 0. 42 0. 25 O. 095 Copper 50 0. 46 0. 25 0. 10

These samples were exposed outdoors for 8 months in the manner described in Example 2. Results of mildew and algae growth of the fabrics after exposure are shown in Table II.

TABLE II.EXTENT OF MILDEW AND ALGAE INHIBITION IMPARIED TO THE COTTON POUNDS DESCRIBED IN TABLE I "T=Trace oi mildew or algae, X=Visible mildew or algae, 0=Completely free of mildew and algae.

The untreated scoured duck control exposed simultaneously showed heavy mildew and algae growth at four months and the amount increased over the 8-month period. At all times the untreated cotton showed more mildew and algae than the treated samples.

We claim:

1. A process for rendering a cellulosic textile fabric resistant to the attack of micro-organisms which process consists of impregnating the cellulosic textile fabric with an aqueous-solvent emulsion system comprising a conventional alkyd resin binder, to which has been added a sufiicient amount of a water insoluble metal telluride to insure the deposition of at least 0.10% by weight of tellurium on the finished fabric.

References Cited UNITED STATES PATENTS 1,536,379 5/1925 Dickens 16 7-14 2,357,526 9/1944 Light et al 117-16 1 2,399,873 5/1946 Littman et a1. 117-14 3 X WILLIAM D. MARTIN, Primary Examiner.

T. G. DAVIS, Assistant Examiner.

FABRIC BY THE COM- 

1. A PROCESS FOR RENDERING A CELLULOSIC TEXTILE FABRIC RESISTANT TO THE ATTACK OF MICRO-ORGANISMS WHICH PROCESS CONSISTS OF IMPREGNATING THE CELLULOSIC TEXTILE FABRIC WITH AN AQUEOUS-SOLVENT EMULSION SYSTEM COMPRISING A CONVENTIONAL ALKYD RESIN BINDER, TO WHICH HAS BEEN ADDED A SUFFICIENT AMOUNT OF A WATER INSOLUBLE METAL TELLURIDE TO INSURE THE DEPOSITION OF AT LEAST 0.10% BY WEIGHT OF TELLURIUM ON THE FINISHED FABRIC. 